Method of forming header extension, and vehicle structure

Abstract

A method of forming a header extension coupling a front header and a roof side inner includes: electrically heating a part of a material to a temperature of not less than a hardening temperature such that a front header side is heated to the temperature of not less than the hardening temperature and a roof side inner side is heated to a temperature of less than the hardening temperature; and press-forming the material after the electrical heating into the shape of the header extension; and hardening the material by quenching. In this way, a vehicle structure can be provided such that the bending mode under application of a load to the roof can be appropriately controlled, and productivity can be improved.

1 . A method of forming a header extension connecting a front header and a roof side inner comprising:
 electrically heating a part of a material to a temperature of not lower than a hardening temperature thereof such that a front header side is heated to the temperature of not lower than the hardening temperature and a roof side inner side is heated to a temperature lower than the hardening temperature; and   press-forming the material after the electrical heating into a shape of the header extension and hardening the material by quenching.   
     
     
         2 . The method according to  claim 1 , wherein
 the header extension is extended from one end to which the front header is ended to the other end to which the roof side inner is bonded, and comprises a flange having a face perpendicular to the extended direction of the header extension so as to be bonded with the roof side inner by face bonding,   the material comprises a shape in which an area at the roof side inner side has a wider width across the extended direction of the header extension than the other area, and an area at the front header side has a narrower width across the extended direction of the header extension than the other area, and   the electrical heating is performed along the extended direction of the header extension.   
     
     
         3 . A vehicle structure comprising:
 a front header;   a roof side inner; and   a header extension connecting the front header and the roof side inner,   wherein in the header extension, a front header side is a hardened section, and a roof side inner side is an unhardened section.